Earthquake: the shaking of the rocks underneath the crust Stress: a type of energy that changes a rock's shape or volume Shearing: energy that pulls the weight of a rock in two opposite directions Tension: energy that pulls on the side of the rock making it skinnier in the middle Compression: a force that pushes pieces of rock together until it breaks Deformation: any change of volume or shape in our planet's crust Fault: a break in the Earth's surface where slabs of crust slip past each other Strike-slip fault: a fault where rocks on either side of the fault slip past each other sideways with a little up-and-down movement Normal fault: a fault where it's at an angle so one block of rock lies above the fault while the other block of rock lies below the fault Hanging wall: half of the fault that lies on top Footwall: half of the fault which lies on the bottom Reverse fault: a fault which has the same structure as a normal but the rock's direction are switched Fault block mountains: a fault that is created when a normal fault uplifts a block of rock Folds: bends in the rock that form when compression shortens and thickens part of Earth's crust Anticline: a fold in a rock which makes it bend upward into an arch Syncline: a fold in a rock which makes it bend downward to form a bowl Plateau: a large area of flat land made high above sea level
Outline
Stress in the Crust
there are three types of stress in the crust
Shearing
can cause rock to break or change its shape
Tension
stretches the rock which causes the middle to become thinner
Compression
squeezes the rock until it folds or breaks
Kinds of Faults
Strike-Slip fault
the rocks on either side have an up-and-down motion while they slip past each other
Normal fault
one block is on top and another is below, the top half of the fault is the hanging wall, the bottom half is the footwall
Reverse fault
same as normal fault but the rocks move in the opposite directions
Friction among faults
rocks in a fault move only if there is friction
friction exits because the surface is not smooth
Mountain Building
Mountains can be formed by faulting
Mountains can also be formed by folding
Anticlines and Syniclines
Geologists use these words to describe the upward an downward folds in rock
Plateaus
forces that raise mountains can also raise plateaus
Table of Contents
Earth's Crust in Motion
Vocabulary
Earthquake: the shaking of the rocks underneath the crustStress: a type of energy that changes a rock's shape or volume
Shearing: energy that pulls the weight of a rock in two opposite directions
Tension: energy that pulls on the side of the rock making it skinnier in the middle
Compression: a force that pushes pieces of rock together until it breaks
Deformation: any change of volume or shape in our planet's crust
Fault: a break in the Earth's surface where slabs of crust slip past each other
Strike-slip fault: a fault where rocks on either side of the fault slip past each other sideways with a little up-and-down movement
Normal fault: a fault where it's at an angle so one block of rock lies above the fault while the other block of rock lies below the fault
Hanging wall: half of the fault that lies on top
Footwall: half of the fault which lies on the bottom
Reverse fault: a fault which has the same structure as a normal but the rock's direction are switched
Fault block mountains: a fault that is created when a normal fault uplifts a block of rock
Folds: bends in the rock that form when compression shortens and thickens part of Earth's crust
Anticline: a fold in a rock which makes it bend upward into an arch
Syncline: a fold in a rock which makes it bend downward to form a bowl
Plateau: a large area of flat land made high above sea level
Outline
Stress in the Crust
Kinds of Faults
Friction among faults
Mountain Building
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